docs: def dbclass(self, value):
          """Set the connection's dbclass property.
  
          Args:
              value:  New dbclass value. String.
  
          Returns:
              Nothing.
          """
  
          if not is_valid_dbclass(value):
              raise AttributeError("'{}' is not a valid database type".format(value))
  
          self._class = value
          self._connectionXML.set('class', value)